Mr. Santos treated his students and adult chaperones to a movie for winning the state contest. There were 20 fewer adults than students that attended. The movie theater charged $ 4 for each student and $ 6 for each adult. If Mr. Santos spent $ 180 on movie tickets, write a system of equations that represents the number of adult tickets, a, and the number of students tickets, s, that were purchased

The table below shows the approximate masses of a dust particle and a grain of pollen. dust particle 0.000000778 g grain of pollen 0.00000000155 g the mass of a dust particle can be estimated and written in the form a × 10^b, where a = 8 and b = the mass of a grain of pollen can be estimated and written in the form a × 10^b, where a = 2 and b = based on the estimates, the mass of a dust particle is approximately blank times larger than the mass of a grain of pollen.